Re: [RFC PATCH] scripts: checkpatch.pl: remove obsolete in_atomic rule

[Michal Hocko]

On Sat 04-11-17 03:08:06, Yang Shi wrote:
> checkpatch.pl still reports the below in_atomic warning:
> 
> WARNING: use of in_atomic() is incorrect outside core kernel code
> +       if (in_atomic())
> 
> But, in_atomic() has been used outside kernel dir for a long time, and
> even drivers. So, remove the obsolete rule even though they can be
> ignored.

NAK. in_atomic is tricky and shouldn't be used. I would bet most of the
usage is simply broken. See more http://lkml.kernel.org/r/20171106100558.GD3165@xxxxxxxxxxxxxxxxxxxxxx
 
> Signed-off-by: Yang Shi <yang.s@xxxxxxxxxxxxxxx>
> CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
> Not sure if removing the obsolete rule is preferred by checkpatch.pl, anyway
> it sounds not make sense to keep invalid rule.
> 
>  scripts/checkpatch.pl | 11 -----------
>  1 file changed, 11 deletions(-)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 8b80bac..e8cf94f 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -6231,17 +6231,6 @@ sub process {
>  			     "Using $1 should generally have parentheses around the comparison\n" . $herecurr);
>  		}
>  
> -# whine mightly about in_atomic
> -		if ($line =~ /\bin_atomic\s*\(/) {
> -			if ($realfile =~ m@^drivers/@) {
> -				ERROR("IN_ATOMIC",
> -				      "do not use in_atomic in drivers\n" . $herecurr);
> -			} elsif ($realfile !~ m@^kernel/@) {
> -				WARN("IN_ATOMIC",
> -				     "use of in_atomic() is incorrect outside core kernel code\n" . $herecurr);
> -			}
> -		}
> -
>  # whine about ACCESS_ONCE
>  		if ($^V && $^V ge 5.10.0 &&
>  		    $line =~ /\bACCESS_ONCE\s*$balanced_parens\s*(=(?!=))?\s*($FuncArg)?/) {
> -- 
> 1.8.3.1

-- 
Michal Hocko
SUSE Labs